I let a local talk me into a $500 bike rental.

I had the chance to check out a public bike share in Montreal for the first time last year. But since I couldn't read the instructions in French, I asked a local to explain the process.

It was free for the first 45 minutes, he said, and I would be charged a couple of extra bucks every hour after that.

Unfortunately for me, he forgot to mention the $250 security deposit the company applied to my credit card for each bike. I rented two.

Good thing I had used a credit card and not my debit card, because it took well over a week for the temporary charge to disappear.

2/

I forgot to tell my bank about a D.C. road trip.

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After President Obama was elected in 2008, I hatched a plan for the ultimate 48-hour road trip — from Athens, Ga. to D.C. for his Inaugural address.

I just forgot to tell my bank about it.

Apparently, swiping my debit card at a slew of gas stations up and down the East coast in such a short period of time spelled "FRAUD" to them. They froze my account and I wound up stranded at a North Carolina pit stop until I could get a representative on the phone to correct the mistake.

If I had been overseas, it would have been an even bigger nightmare.

3/

I lost some serious haggling potential by not learning the native tongue.

Although I can count the number of Portuguese words I know on two hands, I hoped my decent Spanish skills would help me get by on a recent trip to Brazil.

I was dead wrong. I could read signs well enough, but anything spoken sounded like pure gibberish.

Learning the language would have made haggling so much easier — especially when ordering at restaurants.

4/

I trusted my roommate in Chile while she was robbing me blind.

When I moved to Chile after college, I decided to rent a room in a nice apartment from a local. She was trustworthy enough, and I let myself get comfortable after a couple of months. Then she took on a new tenant.

At the time, I kept a couple hundred U.S. dollars for emergencies sealed in a bag in an unlocked drawer in my bedroom dresser. Two weeks after the new girl moved in, I started to notice small denominations were missing. Then a whole $100 was gone. And so was I, after I confronted her about the theft and moved out.

These days, the only emergency cash I carry on extended trips is in a savings account I can access from just about any ATM.

5/

I relied on pricey cabs like a security blanket.

Cabs are ubiquitous in any major city, but they're also a great way to waste money.

Before I even get on a plane, I research the public transportation options at my destination. Google Maps works just as well overseas and although there's always an awkward learning curve when you try hopping a bus in a foreign country, it's definitely worth the effort. In some cities like Rio, Santiago, and Paris, I found the subway systems just as good — if not better — than New York's.

I paid $6 USD for a 30-minute air-conditioned shuttle from Rio's airport, versus the $20 some cab drivers were quoting me. And public buses are the best ways to get a cheap tour of a new place, I've found.

I wasted a ton of cash thanks to an early phobia of foreign foods.

At 18, I still considered mac 'n cheese to be the height of fine dining. It wasn't long before I realized I was only hurting myself — and my wallet — by turning my nose up at the local cuisine.

Not only is it most likely 10 times cheaper than what you might find at any familiar chain restaurant near your hotel, the food is often just as much a part of a country's culture as any museum or national park.

Nowadays, I like to carve out a four- or five-block section on a map and walk around until I find a place that looks appetizing. Lunchtime is almost always more affordable.

7/

I was duped far too many times by quick-handed fruit vendors.

A Chilean friend recently reminded me of one of the easiest ways to get duped by fruit vendors at fresh air markets.

Vendors love displaying new produce up front and stuffing the old ones behind the pile. I would often ask for a few avocados or tomatoes and walk away with a bag full of bruised, or near-rotten veggies they snuck in from the back of the stack.

I've learned to physically hand the vendors the produce I want and watch (politely) as they bag it.

8/

I assumed every store would list prices in the local currency.

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On my way home from Brazil, I was overcome by a bout of food poisoning. Sick and freezing cold, I hightailed it to the airport's duty-free shop to pick up something for the flight ahead.

I settled on a sweatshirt priced at $78. The Brazilian Real is about 2:1 to the U.S. dollar these days and I was desperate enough to justify the USD $40 purchase as a health emergency.

It wasn't until I got home that I realized I'd been too hasty. My entire purchase rang up in U.S. dollars — not Reais. It's without a doubt the most expensive souvenir I've ever purchased.

I went cliff-diving in Jamaica without traveler's insurance.

When I found myself in stunning Negril, Jamaica last summer, I took one look at a group of local divers doing back flips off 75-foot cliffs and I knew I was in.

The jump didn't exactly go as planned.

The back of my left leg slapped the water like a fist punching through glass and just as the force knocked the wind out of my chest, I felt my teeth clamp down on my tongue.

I hobbled away with a watermelon-sized bruise on my thighs and a backache that lasted long after my vacation. I was lucky. Had I been seriously injured, I could have faced thousands of dollars in medical bills my insurer would never cover.

10/

I turned myself into a walking theft-magnet by lugging all my gadgets around.

One of the most difficult lessons I've learned about traveling wisely is to leave behind almost anything I can plug into a wall.

Chances are it is a pricey gadget (laptop, e-reader, mp3 player, etc.) that not only makes me an easy target for pickpockets, but could distract from a lot of the pleasures of travel in the first place.

Unless you've taken out an insurance policy or have extended warranties on your electronics, chances are you're better off leaving them behind. You'll only find yourself wasting time worrying about them, and most cities have public Internet cafes perfect for keeping in touch along your journey.

11/

I tortured myself in grimy hostels to save a few bucks.

I've arrived at hostels that were rated four-stars on review websites only to find moldy sheets, dirty bathrooms and zero secure storage offerings. The problem about trusting reviews is that every traveler is different and tastes vary widely.

Now, I look for budget-friendly lodging options that won't make my skin crawl.

If you're wary of Airbnb or Couch Surfing (both of which I have used successfully and often), try haggling down room rates at Bed & Breakfasts or smaller inns, especially if you're traveling in the off-season. They might be desperate enough to fill their beds to shave down their rates.

12/

I let exhaustion get in the way of finding fair-priced lodging.

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There comes a time during any extended trip that traveler's fatigue sets in. You're sick of haggling and being misunderstood by locals and miming for directions to the nearest bathroom.

So you get lazy, like I did when I arrived in an exhausted heap in Aguas Calientes, Peru. I was on my way to Machu Picchu and had spent the previous night tossing and turning in a nightmarish hostel I found online.

After arriving, I booked a room in the first clean hostel I found and forked over the $30 USD they requested without a second thought. It wasn't until I met a pair of backpackers the next day that I realized I'd been fleeced.

They each paid $8 USD a night — at a hostel two blocks from where I'd chosen.

I let my guidebook distract me from the real sights.

When you're plunking down a few thousand dollars on a trip, it's easy to think that seeing the biggest and most popular sights is the only way to justify the cost.

I've learned otherwise.

Odds are you wouldn't find a town like Constitución, Chile on a map — or any guidebook for that matter — but I hitch-hiked there in the back of a pickup truck and spent four days at a seaside campsite that looked like it belonged in a Rogers & Hammerstein book.